samples/png/pngdemo.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        pngdemo.cpp
   3 // Purpose:     Demos PNG reading
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // For compilers that support precompilation, includes "wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #ifdef __BORLANDC__
  16 #pragma hdrstop
  17 #endif
  18
  19 #include "wx/image.h"
  20
  21 #include "pngdemo.h"
  22
  23 MyFrame   *frame = (MyFrame *) NULL;
  24 wxBitmap  *g_TestBitmap = (wxBitmap *) NULL;
  25
  26 IMPLEMENT_APP(MyApp)
  27
  28 bool MyApp::OnInit(void)
  29 {
  30   wxImage::AddHandler(new wxPNGHandler);
  31
  32   // Create the main frame window
  33   frame = new MyFrame((wxFrame *) NULL, _T("wxPNGBitmap Demo"), wxPoint(0, 0), wxSize(300, 300));
  34
  35 #if wxUSE_STATUSBAR
  36   // Give it a status line
  37   frame->CreateStatusBar(2);
  38 #endif // wxUSE_STATUSBAR
  39
  40   // Make a menubar
  41   wxMenu *file_menu = new wxMenu;
  42   wxMenu *help_menu = new wxMenu;
  43
  44   file_menu->Append(PNGDEMO_LOAD_FILE, _T("&Load file"),                _T("Load file"));
  45   file_menu->Append(PNGDEMO_SAVE_FILE, _T("&Save file"),                _T("Save file"));
  46   file_menu->Append(PNGDEMO_QUIT, _T("E&xit"),                _T("Quit program"));
  47   help_menu->Append(PNGDEMO_ABOUT, _T("&About"),              _T("About PNG demo"));
  48
  49   wxMenuBar *menu_bar = new wxMenuBar;
  50
  51   menu_bar->Append(file_menu, _T("&File"));
  52   menu_bar->Append(help_menu, _T("&Help"));
  53
  54   // Associate the menu bar with the frame
  55   frame->SetMenuBar(menu_bar);
  56
  57   MyCanvas *canvas = new MyCanvas(frame, wxPoint(0, 0), wxSize(100, 100));
  58
  59   // Give it scrollbars: the virtual canvas is 20 * 50 = 1000 pixels in each direction
  60 //  canvas->SetScrollbars(20, 20, 50, 50, 4, 4);
  61   frame->canvas = canvas;
  62
  63   frame->Show(true);
  64
  65 #if wxUSE_STATUSBAR
  66   frame->SetStatusText(_T("Hello, wxWidgets"));
  67 #endif // wxUSE_STATUSBAR
  68
  69   return true;
  70 }
  71
  72 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
  73     EVT_MENU(PNGDEMO_QUIT,      MyFrame::OnQuit)
  74     EVT_MENU(PNGDEMO_ABOUT,     MyFrame::OnAbout)
  75     EVT_MENU(PNGDEMO_LOAD_FILE, MyFrame::OnLoadFile)
  76     EVT_MENU(PNGDEMO_SAVE_FILE, MyFrame::OnSaveFile)
  77 END_EVENT_TABLE()
  78
  79 // Define my frame constructor
  80 MyFrame::MyFrame(wxFrame *frame, const wxString& title, const wxPoint& pos, const wxSize& size):
  81   wxFrame(frame, wxID_ANY, title, pos, size)
  82 {
  83   canvas = (MyCanvas *) NULL;
  84 }
  85
  86 // frame destructor
  87 MyFrame::~MyFrame()
  88 {
  89     if (g_TestBitmap)
  90     {
  91         delete g_TestBitmap;
  92         g_TestBitmap = (wxBitmap *) NULL;
  93     }
  94 }
  95
  96 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
  97 {
  98     Close(true);
  99 }
 100
 101 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 102 {
 103     (void)wxMessageBox(_T("PNG demo\nJulian Smart (c) 1998"),
 104             _T("About PNG Demo"), wxOK);
 105 }
 106
 107 void MyFrame::OnSaveFile(wxCommandEvent& WXUNUSED(event))
 108 {
 109 #if wxUSE_FILEDLG
 110     wxString f = wxFileSelector( wxT("Save Image"), (const wxChar *)NULL,
 111                                  (const wxChar *)NULL,
 112                                  wxT("png"), wxT("PNG files (*.png)|*.png") );
 113
 114     if (f.empty())  return;
 115
 116     wxBitmap *backstore = new wxBitmap( 150, 150 );
 117
 118     wxMemoryDC memDC;
 119     memDC.SelectObject( *backstore );
 120     memDC.Clear();
 121     memDC.SetBrush( *wxBLACK_BRUSH );
 122     memDC.SetPen( *wxWHITE_PEN );
 123     memDC.DrawRectangle( 0, 0, 150, 150 );
 124     memDC.SetPen( *wxBLACK_PEN );
 125     memDC.DrawLine( 0, 0, 0, 10 );
 126     memDC.SetTextForeground( *wxWHITE );
 127     memDC.DrawText( _T("This is a memory dc."), 10, 10 );
 128
 129     memDC.SelectObject( wxNullBitmap );
 130
 131     backstore->SaveFile( f, wxBITMAP_TYPE_PNG, (wxPalette*)NULL );
 132
 133     delete backstore;
 134 #endif // wxUSE_FILEDLG
 135 }
 136
 137 void MyFrame::OnLoadFile(wxCommandEvent& WXUNUSED(event))
 138 {
 139 #if wxUSE_FILEDLG
 140     // Show file selector.
 141     wxString f = wxFileSelector(wxT("Open Image"), (const wxChar *) NULL,
 142                                     (const wxChar *) NULL, wxT("png"),
 143                                     wxT("PNG files (*.png)|*.png"));
 144
 145     if (f.empty())
 146         return;
 147
 148     if ( g_TestBitmap )
 149         delete g_TestBitmap;
 150
 151     g_TestBitmap = new wxBitmap(f, wxBITMAP_TYPE_PNG);
 152     if (!g_TestBitmap->Ok())
 153     {
 154         delete g_TestBitmap;
 155         g_TestBitmap = (wxBitmap *) NULL;
 156     }
 157
 158     canvas->Refresh();
 159 #endif // wxUSE_FILEDLG
 160 }
 161
 162 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
 163     EVT_PAINT(MyCanvas::OnPaint)
 164 END_EVENT_TABLE()
 165
 166 // Define a constructor for my canvas
 167 MyCanvas::MyCanvas(wxWindow *parent, const wxPoint& pos, const wxSize& size):
 168  wxScrolledWindow(parent, wxID_ANY, pos, size)
 169 {
 170 }
 171
 172 // Define the repainting behaviour
 173 void MyCanvas::OnPaint(wxPaintEvent& WXUNUSED(event))
 174 {
 175     wxPaintDC dc(this);
 176     dc.SetPen(* wxRED_PEN);
 177
 178     int i;
 179     for ( i = 0; i < 500; i += 10)
 180     {
 181         dc.DrawLine(0, i, 800, i);
 182     }
 183     if ( g_TestBitmap && g_TestBitmap->Ok() )
 184     {
 185         wxMemoryDC memDC;
 186         if ( g_TestBitmap->GetPalette() )
 187         {
 188             memDC.SetPalette(* g_TestBitmap->GetPalette());
 189             dc.SetPalette(* g_TestBitmap->GetPalette());
 190         }
 191         memDC.SelectObject(* g_TestBitmap);
 192
 193         // Normal, non-transparent blitting
 194         dc.Blit(20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC, 0, 0, wxCOPY, false);
 195
 196         memDC.SelectObject(wxNullBitmap);
 197     }
 198
 199     if ( g_TestBitmap && g_TestBitmap->Ok() )
 200     {
 201         wxMemoryDC memDC;
 202         memDC.SelectObject(* g_TestBitmap);
 203
 204         // Transparent blitting if there's a mask in the bitmap
 205         dc.Blit(20 + g_TestBitmap->GetWidth() + 20, 20, g_TestBitmap->GetWidth(), g_TestBitmap->GetHeight(), & memDC,
 206             0, 0, wxCOPY, true);
 207
 208         memDC.SelectObject(wxNullBitmap);
 209     }
 210 }